Alois thoma



A.TH 0MA. Rening stee|.

No. 70,048. Patented Oct. 22. 1867.

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AL'OIS THOMA, 0F NEW YORK,.N. Y., ASSIGNOR TO HlMSELIi-S. BROMBERG, i 'i AND ARTEMUSW. W ILDER, OF SAME PLACE.

Letters r.Patent No. 70,018 datcrfctobcr 22,v 1867.

IMPROVED FURNAE POB. MEI'IN G AND PURIPYING STEEL.

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TO ALL WHOM IT MAY CONCERN: i Be it known that I, ALOIS THOMA, of the city, county, and State of New York, have invented a new and improved Furnace for Smelting Steel; and I do hereby declare that the followingr is a. full, clear, and enact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming a part of this specification, in which Figure 1 represents a horizontal sectional view of my improved smclting-furnace, the planeof section "'being indicated by the line at mutig. 2. i

Figure 2 is alongitudinal central sectional elevation of the same. Figure 3 is an end view, partly in section, of the same. Similar letters of reference indicate corresponding parts. This invention .relates to a new furnace for smelting steel, and for producing cast steel of the best quality from steel of ordinary or inferior kind. To do this, I melt the steel in an open pan or vessel, which is itted in a Y suitable furnace. I-Ieretofore steel had to be molten in crucibles, which are not only very expensive, but which also require 'a very large amount of heat to melt the material in their inside. `Illy doing away with the use of the cru-cibles, and by melting theA steel in an open pan, I reduce the ef-xpense of the steel-smelting process to-a considerable degree, as the pan is notonl'y much cheaper, and can bc used frequently, but as, also, considerable fuel is saved, thesteel being molten much Aquicker than in the cruciblcs. Furthermore,v the arrangement of'my furnace does not confine me to the useof any certain kind of fuel, and the expense of smelting may thusv be still more reduced by using a cheaper hind of fuel. y

A represents a furnace, made of {ire-brick oriother suitable material, and consisting of three main divisions: the fireplace B, the melting-oven C, .and'the air-heating chamber l). p 'lhe chambers B and C are connected by a channel, a, and the chambers C and D by a channel, b, as shown in fig. 2. VIn the rcplace B are arranged a' suitable grate, c, and a channel, e, above` it, to put in the fuel. A door, d, in the end of the furnace, can be used for cleaning the fireplace. f is a pipe for conducting the requisite amount of drauffht to the tire; y is the D v ash-pit, and t-a door to the same. The channel a, through which the flame passes yto the oven C, inelincs towards the oven, as shown in'fig. 2. Above the channel a .is arranged, in the furnace, a pipe orrcsorvoir, t', from which an opening, j, extends to the channel a, connecting thc same with the reservoir z', as is clearly shown iu'g. 2. The opening j is arranged obliquely, and wider at its lower end, so that a blast of air blown through it will throw the llame upon the surface of the channel a, and detain itV there for a short timefarrd will also force the llame over and through the surface of the steel in the oven. As the blast forces the llames down, they are retarded in 'their progress, and thereby all dust that might arise from the fuel will be retained, and will be prevented from being carried off by the llame. ,Thereby the llame is purified, which itinust be inorder te produce pure cast steel. All the-gases carried off with the llame will bc completely burned by the action of the blast` and a most intense heat will be crea-ted in the channel a.'

The interior of the hearth or oven C can be reached through doors 7c k', arranged in the opposite sides of the same. Through the smaller door 7c thc oven is filled and emptied, while through the larger door it the pan lis inserted. This pan consists of three, more or lcss, sections,lwhich, when arranged together, form an open, shullowpan'or vessel, l, which corresponds in its outer shape to the shape of the oven C.

The hearth is made of goed fire-brick or other suitable materialf Upon-its surface is placed a-laycr of `goed quartz-sand, which must be well levelled and rmly stamped. Then the sections of thc pan are inserted through the door It', so that they will rest upon the sand-sole m.` A small space should be left betwccnithe rim of the pan and the wall of the oven, which is filled, aswell as the crevices between the sections of the pan,

with quartz-sand which has been mixed in wet clay. The upper parts of these crcvicesarc filled witlta mixture of quartz,v lime, and salt. When heat is applied, this latter mixture will melt, and will connect the sections of the pan so as to make a smooth bottom in the pan, while the addition of the quartz makes this cement so brittle that it can be easily broken when the pan is to be removed from the furnace.

The pau Z, as well as the, inner liningof the oven, is best made of goed lire-brick clay, pressed, and, when dry, coated on the lire side with concentrated salt solution, and then thoroughly burned.

The auie, after having passed through the oven, escapes through the channel b into-the air-heating charnber D, in which pipe n is arranged in zigzag lines. The pipe leads to the reservoir and carries the blastof air to the fire. The products of combustion, entering the chamber D, heat the pipe n, und thereby the blast is carried to the fire. These pipes, not being directly in the tire, as usual, .cannot leak without it being noticed and easily repaired. The products of combustion are finally carried o through a chimney, E.

The steel to be molten is placed in the pan Z, and covered with a thin layer of Huid dross, which protects it from the direct inuenec of thcllanie, so that only the heat of the dame will act upon the steel, but not any gases contained therein. v

By the arrangement of the blast-channel j, the flanie is blown over the surface of the steel, and the heat thus brought against the steel is higher than could ever be produced in any other furnace in which iron or steel is treated, and therefore the sinelting process will occupy but comparatively short time. Therefore, also, large quantitiesiof steel can bc'molten in this furnace. Y

It is advisable to test the steel during the melting process, so that, if required, its quality can be improved by adding bar' iron or hard steel. A hole, o, is arranged in the door k', and in the rim ofthe pan l, to discharge the steel when finished. Where crncibles are used, steel cannot be thus treated, improved, or tested during the melting process.

By the Bessemer' process of producing steel, good steelfor cutting-tools is only accidentally produced, the general quality being impure, mixed with sulphur and phosphorus. Such impure steel can be'converted into perfctly pure cast steel in my furnace. I v

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, isi- 1. Snielting steel in an open pan, by blowing a purified flame ovcr'the surface of the steel in the pan, substantially as herein shown and described.

-2. The pan?, in which the steel to be slnelted is placed, when said pan is made in sections, so that it can be easily inserted and removed through the narrow doors of the furnace, substantially as herein shown and described.

Connecting the smelting-oven C with the air-heating chamber D, by means of a chamber, b,"so that the air pipe n is heated in the chamber D, and not in the oven C, substantiallyv as and for' the purpose herein shown and described.

4; So arranging a furnace for sinelting steel that the steel can be tested and treated duri-ng the smeltng process, substantially as herein shown and described. l A

5. The chambers C, D, and E, when connected by channels a and b, and when combined with the reservoir' blast-channelj, pan l, and pipe n, all made, arranged, and operating substantially as and for the purpose herein .shown and described. l l

6. Making the blast-channeljwider at its lower end, and arranging itobliquely in the furnace, substantially as and for the purpose herein shown and described..

ALOIS THOMA.

Witnesses:

A. V Bumsen, ALEX. F.. ltonnnrs. 

